Electroosmotic coupled with particle-assisted deep eutectic solvent flotation for the enrichment of eugenol from clove

Eugenol has many biological and pharmacological activities such as antioxidant, anticancer, anti-inflammatory, antibacterial and anesthetic.   In view of its wide range of beneficial activities, it is crucial to establish a method for the separation and purification of active components from clove. In this study, an electroosmotic coupled with particle-assisted deep eutectic solvent flotation method was established for the enrichment of eugenol from clove. Ten deep eutectic solvent (DES) extraction systems based on menthol as the hydrogen bond acceptor (HBA) were screened, and butanol was determined as the hydrogen bond donor (HBD) to prepare the optimal DES as extractant for extracting eugenol. Under the optimum operating conditions including solid–liquid ratio of 1:30, flotation time of 50 min, nitrogen flow rate of 55 mL/min, salt content of 20 g, pH of the clove suspension of 5.2, applied voltage of 15 V, copper electrode at the bottom, the yield of eugenol was 45.89 ± 1.61 mg/g. Compared with other extraction methods, the extraction rate was greatly improved. The electroosmotic coupled with particle-assisted deep eutectic solvent flotation method provides a green and efficient enrichment strategy for natural product, which has broad application prospects.